bugfix:#I6YMV4【任务栏】任务栏尺寸为小和中时，任务栏下方有缝隙

src/gui/kernel/qhighdpiscaling_p.h

@@ -294,6 +294,29 @@ inline QRegion toNativeLocalRegion(const QRegion &pointRegion, const QWindow *wi
     return scale(pointRegion, QHighDpiScaling::factor(window));
 }
 
+inline QRect toNativePixelsWithCalibration(const QRect &rect, const QWindow *window)
+{
+    if (!QHighDpiScaling::isActive() || !window)
+        return rect;
+
+    QWindow *win = const_cast<QWindow *>(window);
+    QPoint convertAfterSum = rect.topLeft();
+
+    QPoint convertAtEach = QHighDpi::toNativePixels(rect.topLeft(), window);
+
+    while ((win = win->parent()) && !win->isTopLevel()){
+        convertAfterSum += win->geometry().topLeft();
+        convertAtEach += QHighDpi::toNativePixels(win->geometry().topLeft(), win);
+    }
+    QPoint renderPos = QHighDpi::toNativePixels(convertAfterSum, window);
+    QPoint diff = renderPos - convertAtEach;
+
+    QPoint newPoint = QHighDpi::toNativePixels(rect.topLeft(), window) + diff;
+    QSize newSize = QHighDpi::toNativePixels(rect.size(), window);
+
+    return QRect(newPoint, newSize);
+}
+
 } // namespace QHighDpi
 #else // QT_NO_HIGHDPISCALING
 class Q_GUI_EXPORT QHighDpiScaling {

src/gui/kernel/qwindow.cpp

@@ -1745,7 +1745,7 @@ void QWindow::setGeometry(const QRect &rect)
         if (newScreen && isTopLevel())
             nativeRect = QHighDpi::toNativePixels(rect, newScreen);
         else
-            nativeRect = QHighDpi::toNativeLocalPosition(rect, newScreen);
+            nativeRect = QHighDpi::toNativePixelsWithCalibration(rect, this);
         d->platformWindow->setGeometry(nativeRect);
     } else {
         d->geometry = rect;
@@ -1865,7 +1865,7 @@ void QWindow::setFramePosition(const QPoint &point)
     d->positionPolicy = QWindowPrivate::WindowFrameInclusive;
     d->positionAutomatic = false;
     if (d->platformWindow) {
-        d->platformWindow->setGeometry(QHighDpi::toNativePixels(QRect(point, size()), this));
+        d->platformWindow->setGeometry(QHighDpi::toNativePixelsWithCalibration(QRect(point, size()), this));
     } else {
         d->geometry.moveTopLeft(point);
     }
@@ -1936,7 +1936,7 @@ void QWindow::resize(const QSize &newSize)
     d->positionPolicy = QWindowPrivate::WindowFrameExclusive;
     if (d->platformWindow) {
         if (isTopLevel()) {
-            d->platformWindow->setGeometry(QHighDpi::toNativePixels(QRect(position(), newSize), this));
+            d->platformWindow->setGeometry(QHighDpi::toNativePixelsWithCalibration(QRect(position(), newSize), this));
         } else {
             d->platformWindow->setGeometry(QRect(QHighDpi::toNativeLocalPosition(position(), this),
                                                  QHighDpi::toNativePixels(newSize, this)));

src/plugins/platforms/xcb/qxcbbackingstore.cpp

@@ -241,6 +241,18 @@ void QXcbBackingStoreImage::resize(const QSize &size)
                                   << "] destroyed SHM segment due to resize to" << size;
             }
         } else {
+            if (QHighDpiScaling::isActive()) {
+                auto windows = QGuiApplication::allWindows();
+                for (auto window : windows) {
+                    if (!window->isTopLevel() && m_backingStore->window()->isAncestorOf(window) && window->handle()) {
+                        QRect nativeRect = QHighDpi::toNativePixelsWithCalibration(window->geometry(), window);
+                        if (nativeRect != QHighDpi::toNativePixels(window->geometry(), window)) {
+                            window->handle()->setGeometry(nativeRect);
+                        }
+                    }
+                }
+            }
+
             // Destroy shared memory segment if it is double (or more) of what we actually
             // need with new window size. Or if the new size is bigger than what we currently
             // have allocated.
@@ -602,6 +614,7 @@ void QXcbBackingStoreImage::shmPutImage(xcb_drawable_t drawable, const QRegion &
 {
     for (const QRect &rect : region) {
         const QPoint source = rect.translated(offset).topLeft();
+        int r= 0;
         xcb_shm_put_image(xcb_connection(),
                           drawable,
                           m_gc,
@@ -609,7 +622,7 @@ void QXcbBackingStoreImage::shmPutImage(xcb_drawable_t drawable, const QRegion &
                           m_xcb_image->height,
                           source.x(), source.y(),
                           rect.width(), rect.height(),
-                          rect.x(), rect.y(),
+                          rect.x() + r, rect.y(),
                           m_xcb_image->depth,
                           m_xcb_image->format,
                           0, // send event?

src/plugins/platforms/xcb/qxcbwindow.cpp

@@ -565,13 +565,26 @@ void QXcbWindow::destroy()
 
 void QXcbWindow::setGeometry(const QRect &rect)
 {
+    QXcbScreen *currentScreen = xcbScreen();
+    QXcbScreen *newScreen = parent() ? parentScreen() : static_cast<QXcbScreen*>(screenForGeometry(rect));
+
+    if (window()->isTopLevel()) {
+        // to check whether the bottom of QWindow is intended to be matched to
+        // the bottom of screen or not
+        QRect logicalScreenRect = static_cast<QPlatformScreen*>(newScreen)->screen()->geometry();
+        QRect logicalWinRect = QHighDpi::fromNativePixels(rect, window());
+
+        if (logicalScreenRect.height() == (logicalWinRect.y() + logicalWinRect.height())) {
+            // update height of physical rect
+            QRect *newRect = const_cast<QRect *>(&rect);
+            newRect->setHeight(newScreen->geometry().height() - newRect->y());
+        }
+    }
+
     QPlatformWindow::setGeometry(rect);
 
     propagateSizeHints();
 
-    QXcbScreen *currentScreen = xcbScreen();
-    QXcbScreen *newScreen = parent() ? parentScreen() : static_cast<QXcbScreen*>(screenForGeometry(rect));
-
     if (!newScreen)
         newScreen = xcbScreen();
 
@@ -1407,6 +1420,21 @@ void QXcbWindow::propagateSizeHints()
     QSize baseSize = windowBaseSize();
     QSize sizeIncrement = windowSizeIncrement();
 
+    if (window()->isTopLevel() && minimumSize == maximumSize && !sizeIncrement.isEmpty()) {
+        // to use adjusted values at QXcbWindow::setGeometry
+        minimumSize = rect.size();
+
+        // to adjust values by sizeIncrement
+        if (minimumSize.width() % sizeIncrement.width() != 0) {
+            minimumSize.setWidth((minimumSize.width() / sizeIncrement.width() + 1) * sizeIncrement.width());
+        }
+
+        if (minimumSize.height() % sizeIncrement.height() != 0) {
+            minimumSize.setHeight((minimumSize.height() / sizeIncrement.height() + 1) * sizeIncrement.height());
+        }
+        maximumSize = minimumSize;
+    }
+
     if (minimumSize.width() > 0 || minimumSize.height() > 0)
         xcb_icccm_size_hints_set_min_size(&hints,
                                           qMin(XCOORD_MAX,minimumSize.width()),